Timing device



H. E. WARREN.

TIMING DEVICE.

APPLICATION FILED FEB. 3, 1920- 7 1,408,050, Patented Feb. 28, 1922.

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. UNITED- STATES PATENT OFFICE."

HENRY E. WARREN, F ASHLAND, MASSACHUSETTS, ASSIGNOR TO GENERAL ELEO-= TRIO COMPANY A CORPORATION OF NEW "YORK.

TIMING DEVICE.

Specification of Letters Patent. Patented Feb 28, 1922 Application filed February 3, 1920. Serial No. 356,107.

To all whom it may concern:

Be it known that I, HENRY E. WARREN, a citizen of the United States, residing at Ashland, county of Middlesex, State of Massachusetts, have invented certain new and useful Improvements in Timing Devices, of which the following is a specifica- 'tion.

This invention relates to timing devices and more particularly to a .device used for determining very short intervals of time of the order of a fraction of one second, accurately to within say one hundredth of a second.

The object of my invention is to provide a device functioning as abovestated and making use of the smallest possible numberof parts. With my device it is entirely feasible to measure the time to'within one hundredth of a second elapsing between any two or more events, such for example as the closure of a switch and the response of a relay thereto.

Broadly considered, my invention com prises a constant speed motor of any well known type and a shaft rotated thereby c arrylngone or more wheels frictionally engaging said. shaft. Each of said wheels carries means whereby when it is stopped it performs a timing function; or if later an other one be stopped the relative movement of the two wheels may be readily determined conveniently in time units.

yThe constructionand mode of operation of an apparatusembodying my invention will be understood from the followin description taken in connection with t e accompanying drawings, in which Fig' 1 is a View more or less diagrammatic showing the arrangement of the wheels, the means for driving them and the means for stopping their rotation, and Fig. 2 is a section along the line 22' looking in the direction of the arrows and'showing the arrangement of the means for reading the relative rotation between any two of the disks.

Referring now more in detail to the draw-' ings, in whlchlike reference numerals refer to like parts throughout, the shaft 11 is shown as appropriately geared to a constant I speed motor 12; in this case shown as a selfstarting synchronous motor of the type referred to in my Letters Patent No. 1,283,433. This motor 12 is supplied from a source of supply 14 of alternating current. The shaft 11 is appropriately supported by stationary members 13. Frictionally engaging said shaft 11 are a plurality of members 15, 15' and 15" here shown as wheels havin a large number of fine notches 16 on t eir' peripheries as clearly shown in Fig. 2. These wheels 15, when not restrained, rotate with the shaft 11. The shaft 11 is so geared that it makes one revolution say in one second. It is quite evident that should one of the wheels, say 15", be stopped in any manner at one instant and wheel 15 at a later instant; then if there should be some means for determining the relative movement of said two wheels, 2. correct measure could be had of the length of time elapsing between the stoppage of said wheels.

Any appropriate means ma be used for stopping the rotation of the w eels. In this instance the notches 16. and cooperating pawls v17 are utilized. Said pawlsare appropriately controlled by electromagnets 18, 19 and 20 energized from an appropriate source of powerill, which latter source of power may or may not be the same as the source 14 for driving the synchronous motor 12. The pawls 17 areadapted to be ulled away from engagement'with the note as 16 by means of springs 22. When anyone of said electromagnets .18, 19 and 20 are energized, however, the corresponding pawl is moved into engagement with the notches 16 and the wheel with which said pawl cooperates is stdpped from rotating. The electromagnets 18,.19 and 20 are; made to respond to certain changes in their electric circuits; for example, as shown, to a closing of the circuit. In the drawing a diagrammatic representation is shown of blade switches 23 for performin this change in the circuit, but when the evice is actually used it is entirely feasible to have the closure of the circuit depend upon other acts, such for example as the response of a relay to its shown in hundredths of a second. In =t-his way the relative movement of any two of the disks may be accurately determined. It is evident also that any number of disks may be mounted on shaft 11.

The operation of the device is apparent from the foregoing description. It is only necessary to add that before the device is started, each of the pointers. 25 and 26 must be placed on the zero mark of the cooperating dial 24, and that the wheel is the first to be stopped, then the wheel 15 and lastly the wheel 15, assuming rotation in the di- 7 rection of the arrow in Fig. 2. When de- 15 termining the length of time it takes a relay to close its contacts, this order of closure is always .known. Furthermore, no appreciable error is introduced due to the inertia of -the moving parts, because the amount of lag to the response of the closing of the circuit is the same foreach of the magnets 18,19, and 20, so that the errors are compensated. Furthermore, the parts are all made'extremely light, so that the lag itself is bound to be very small.

While I have shown in the accompanying drawings the preferred embodiment of my device, my invention is not limited thereto, and- I aim in the appended claims to embrace allmodificat-ions falling fairly within the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In combination, a shaft, a pair of rotatable members frictionally mounted upon said shaft so as to be driven thereby, means for driving said mqmbetrs at a uniform speed, means for topping said members at different times, and indicating means carried by said 40 members to indicate their relative movement.

2. In combination, a shaft driven at a uniform speed, a plurality of wheels frictionallymounted upon said shaft so as to be driven thereby, means responsive to the action of electric circuits to control the rotation of said wheels, and means for determining the relative movement of said wheels to each other in time units.

3. In a timing-device, a shaft, a constant speed motor for driving said shaft, a plurality of wheels frictionally mounted upon said shaft so as to be driven thereby, said wheels having fine notches on their peripheries, a pawl for each of said wheels adapted to engage with said notches to stop the rotation thereof, electromagnets for actuating said pawls, adapted to be energized in response to changes in an electric circuit, and means comprising pointers and dials for determining the relative movement of said wheels in time units.

4. In a timing device, a shaft, a constant speed motor for driving said shaft, a plurality of wheels frictionally mounted upon said shaft so as to be driven thereby, means for stopping the rotation of each wheel, electromagnets for actuating said means, and means for determining the relative movement of said wheels in time units.

5. In a timing device, a shaft, a constant speed motor for driving said shaft, a plurality of wheels frictionally mounted upon said shaft so as to be driven thereby, pawls for stopping the rotation of said wheels, means responsive to changes in an electric circuit for actuating said pawls, and means for determining the relative rotation of said wheels.

6. In a timing device, a pair of rotatable members, means for drivlng said members at a uniform speed, means for stopping said 

